BIOTECHNOLOGY
Today is the era of science and technology. Every field of life seems to be influenced by science. In the modern world, micro-organisms are being used to solve the problems faced by mankind.
The shortage of food and medicine has been overcome to some extent by this. Now, the micro-organisms are also used on industrial scale for the solution of problems and welfare of human beings.
This is generally referred to as biotechnology. With the help of biotechnology, medicines for such diseases have been discovered which were assumed incurable in the past.
In this chapter, we will discuss the nature and uses of biotechnology along with its different techniques.
BIOTECHNOLOGY
The use of micro-organisms for the welfare of mankind on industrial scale is called biotechnology.
Biotechnology has great importance for human life, as it provides the solutions of many problems related to human life.
In biotechnology, the fundamental tool is micro-organisms including different types of bacteria, yeast and fungi etc. In biotechnology, the genetic material (DNA) of micro-organisms is used for production of required products.
Deoxyribo Nucleic Acid (DNA)
As you studied in the previous chapter, DNA is the basic genetic material in all the organisms. This is the material for the transfer of traits from one generation to the next generation.
Structure Of DNA
DNA is a coiled double stranded molecule where each strand is a polymer, made up of repeating units known as nucleotides.Each nucleotide is the combination of a nitrogenous base, a phosphate molecule.
There are four types of nitrogenous bases present in DNA molecule. These nitrogenous bases along with their symbols are:
Adenine (A)
Guanine (G)
Cytosine C)
Thymine (T)
Nucleotides are also given four different names in accordance with base making them.
These are:
Adenine Nucleotide
Guanine Nucleotide
Thymine Nucleotide
Cytosine Nucleotide
Each strand of DNA runs in opposite direction to the other strand so both the strands of a double stranded DNA are anti-parallel to each other or they are also called as complementary to each other.
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| Fig 3.1 Structure Of DNA |
DNA REPLICATION
The process in which the DNA of a cell is duplicated to make two similar copies of the parent DNA is called Replication.
DNA replication is one of the most important cellular mechanisms for all life cells to produce offspring. Daring DNA replication first of all DNA molecules starts to separate like the two halved of a zipper.
One by one, the nucleotides of the complementary strands separate from each other. All the four types of nucleotides are already present in the nucleus. These nucleotides join the separated DNA strand to form a new complementary strand on both sides with the help of an enzyme.
The attachment of the new strand with the old strand is performed by the enzyme DNA ligase which is also called the Molecular glue.
In this way, two new double stranded DNA molecules are synthesized having an old strand from the parent DNA and a new strand. These two molecules are exact replica (copies) of each other. (Fig.3.2)
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| Fig 3.2: DNA Replication |
Relationship among DNA,Chromosomes and Genes
Cell is the basic unit of the body of every organism. Nucleus (a membrane bound organelle) is the control centre of the cell. Nucleus has thread-like structures, called chromosomes, inside it.
Genes are present on the chromosomes on specific locations. These are in fact the small pieces of DNA Strand. Genes transfer the traits from parents to off springs. These are said to be the basis of heredity in organisms.
All chromosomes, DNA and genes are closely related to each other. They all rely on each other and are necessary for the presence of each other.
